Support scope information and evaluation in optimized frames

src/runtime.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 10006 matching lines @@
   CONVERT_NUMBER_CHECKED(int, index, Int32, args[1]);
   Heap* heap = isolate->heap();
 
   // Find the relevant frame with the requested index.
   StackFrame::Id id = isolate->debug()->break_frame_id();
   if (id == StackFrame::NO_ID) {
     // If there are no JavaScript stack frames return undefined.
     return heap->undefined_value();
   }
 
-  int deoptimized_frame_index = -1;  // Frame index in optimized frame.
-  DeoptimizedFrameInfo* deoptimized_frame = NULL;
+  int inlined_frame_index = 0;  // Inlined frame index in optimized frame.
 
   int count = 0;
   JavaScriptFrameIterator it(isolate, id);
   for (; !it.done(); it.Advance()) {
     if (index < count + it.frame()->GetInlineCount()) break;
     count += it.frame()->GetInlineCount();
   }
   if (it.done()) return heap->undefined_value();
 
   if (it.frame()->is_optimized()) {
-    deoptimized_frame_index =
+    inlined_frame_index =
         it.frame()->GetInlineCount() - (index - count) - 1;
-    deoptimized_frame = Deoptimizer::DebuggerInspectableFrame(
-        it.frame(),
-        deoptimized_frame_index,
-        isolate);
   }
+  ScopedDeoptimizedFrameInfo deoptimized_frame(
+      it.frame(), inlined_frame_index, isolate);
 
   // Traverse the saved contexts chain to find the active context for the
   // selected frame.
   SaveContext* save = isolate->save_context();
   while (save != NULL && !save->below(it.frame())) {
     save = save->prev();
   }
   ASSERT(save != NULL);
 
   // Get the frame id.
   Handle<Object> frame_id(WrapFrameId(it.frame()->id()), isolate);
 
   // Find source position.
   int position =
       it.frame()->LookupCode()->SourcePosition(it.frame()->pc());
 
   // Check for constructor frame. Inlined frames cannot be construct calls.
   bool inlined_frame =
-      it.frame()->is_optimized() && deoptimized_frame_index != 0;
+      it.frame()->is_optimized() && inlined_frame_index != 0;
   bool constructor = !inlined_frame && it.frame()->IsConstructor();
 
   // Get scope info and read from it for local variable information.
   Handle<JSFunction> function(JSFunction::cast(it.frame()->function()));
   Handle<SerializedScopeInfo> scope_info(function->shared()->scope_info());
   ASSERT(*scope_info != SerializedScopeInfo::Empty());
   ScopeInfo<> info(*scope_info);
 
   // Get the locals names and values into a temporary array.
   //
   // TODO(1240907): Hide compiler-introduced stack variables
   // (e.g. .result)?  For users of the debugger, they will probably be
   // confusing.
   Handle<FixedArray> locals =
       isolate->factory()->NewFixedArray(info.NumberOfLocals() * 2);
 
   // Fill in the values of the locals.
   int i = 0;
   for (; i < info.number_of_stack_slots(); ++i) {
     // Use the value from the stack.
     locals->set(i * 2, *info.LocalName(i));
     if (it.frame()->is_optimized()) {
       // Get the value from the deoptimized frame.
       locals->set(i * 2 + 1,
-                  deoptimized_frame->GetExpression(i));
+                  deoptimized_frame.GetExpression(i));
     } else {
       // Get the value from the stack.
       locals->set(i * 2 + 1, it.frame()->GetExpression(i));
     }
   }
   if (i < info.NumberOfLocals()) {
     // Get the context containing declarations.
     Handle<Context> context(
         Context::cast(it.frame()->context())->declaration_context());
     for (; i < info.NumberOfLocals(); ++i) {
@@ skipping 46 matching lines @@
   // Now advance to the arguments adapter frame (if any). It contains all
   // the provided parameters whereas the function frame always have the number
   // of arguments matching the functions parameters. The rest of the
   // information (except for what is collected above) is the same.
   it.AdvanceToArgumentsFrame();
 
   // Find the number of arguments to fill. At least fill the number of
   // parameters for the function and fill more if more parameters are provided.
   int argument_count = info.number_of_parameters();
   if (it.frame()->is_optimized()) {
-    ASSERT_EQ(argument_count, deoptimized_frame->parameters_count());
+    ASSERT_EQ(argument_count, deoptimized_frame.parameters_count());
   } else {
     if (argument_count < it.frame()->ComputeParametersCount()) {
       argument_count = it.frame()->ComputeParametersCount();
     }
   }
 
   // Calculate the size of the result.
   int details_size = kFrameDetailsFirstDynamicIndex +
                      2 * (argument_count + info.NumberOfLocals()) +
                      (at_return ? 1 : 0);
   Handle<FixedArray> details = isolate->factory()->NewFixedArray(details_size);
 
   // Add the frame id.
   details->set(kFrameDetailsFrameIdIndex, *frame_id);
 
   // Add the function (same as in function frame).
   if (it.frame()->is_optimized()) {
     // Get the function from the deoptimized frame.
-    details->set(kFrameDetailsFunctionIndex, deoptimized_frame->GetFunction());
+    details->set(kFrameDetailsFunctionIndex, deoptimized_frame.GetFunction());
   } else {
     // Get the function from the stack.
     details->set(kFrameDetailsFunctionIndex, it.frame()->function());
   }
 
   // Add the arguments count.
   details->set(kFrameDetailsArgumentCountIndex, Smi::FromInt(argument_count));
 
   // Add the locals count
   details->set(kFrameDetailsLocalCountIndex,
@@ skipping 15 matching lines @@
   // Add flags to indicate information on whether this frame is
   //   bit 0: invoked in the debugger context.
   //   bit 1: optimized frame.
   //   bit 2: inlined in optimized frame
   int flags = 0;
   if (*save->context() == *isolate->debug()->debug_context()) {
     flags |= 1 << 0;
   }
   if (it.frame()->is_optimized()) {
     flags |= 1 << 1;
-    if (deoptimized_frame_index > 0) {
-      flags |= 1 << 2;
-    }
+    flags |= inlined_frame_index << 2;
   }
   details->set(kFrameDetailsFlagsIndex, Smi::FromInt(flags));
 
   // Fill the dynamic part.
   int details_index = kFrameDetailsFirstDynamicIndex;
 
   // Add arguments name and value.
   for (int i = 0; i < argument_count; i++) {
     // Name of the argument.
     if (i < info.number_of_parameters()) {
       details->set(details_index++, *info.parameter_name(i));
     } else {
       details->set(details_index++, heap->undefined_value());
     }
 
     // Parameter value.
     if (it.frame()->is_optimized()) {
       // Get the value from the deoptimized frame.
-      details->set(details_index++, deoptimized_frame->GetParameter(i));
+      details->set(details_index++, deoptimized_frame.GetParameter(i));
     } else {
       if (i < it.frame()->ComputeParametersCount()) {
         // Get the value from the stack.
         details->set(details_index++, it.frame()->GetParameter(i));
       } else {
         details->set(details_index++, heap->undefined_value());
       }
     }
   }
 
@@ skipping 18 matching lines @@
     // by creating correct wrapper object based on the calling frame's
     // global context.
     it.Advance();
     Handle<Context> calling_frames_global_context(
         Context::cast(Context::cast(it.frame()->context())->global_context()));
     receiver =
         isolate->factory()->ToObject(receiver, calling_frames_global_context);
   }
   details->set(kFrameDetailsReceiverIndex, *receiver);
 
-  // Get rid of the calculated deoptimized frame if any.
-  if (deoptimized_frame != NULL) {
-    Deoptimizer::DeleteDebuggerInspectableFrame(deoptimized_frame,
-                                                isolate);
-  }
-
   ASSERT_EQ(details_size, details_index);
   return *isolate->factory()->NewJSArrayWithElements(details);
 }
 
 
 // Copy all the context locals into an object used to materialize a scope.
 static bool CopyContextLocalsToScopeObject(
     Isolate* isolate,
     Handle<SerializedScopeInfo> serialized_scope_info,
     ScopeInfo<>& scope_info,
@@ skipping 15 matching lines @@
                     kNonStrictMode),
         false);
   }
 
   return true;
 }
 
 
 // Create a plain JSObject which materializes the local scope for the specified
 // frame.
-static Handle<JSObject> MaterializeLocalScope(Isolate* isolate,
-                                              JavaScriptFrame* frame) {
+static Handle<JSObject> MaterializeLocalScope(
+    Isolate* isolate,
+    JavaScriptFrame* frame,
+    int inlined_frame_index) {
   Handle<JSFunction> function(JSFunction::cast(frame->function()));
   Handle<SharedFunctionInfo> shared(function->shared());
   Handle<SerializedScopeInfo> serialized_scope_info(shared->scope_info());
   ScopeInfo<> scope_info(*serialized_scope_info);
+  ScopedDeoptimizedFrameInfo deoptimized_frame(
+      frame, inlined_frame_index, isolate);
 
   // Allocate and initialize a JSObject with all the arguments, stack locals
   // heap locals and extension properties of the debugged function.
   Handle<JSObject> local_scope =
       isolate->factory()->NewJSObject(isolate->object_function());
 
   // First fill all parameters.
   for (int i = 0; i < scope_info.number_of_parameters(); ++i) {
+    Handle<Object> parameter;
+    if (frame->is_optimized()) {
+      parameter = Handle<Object>(deoptimized_frame.GetParameter(i));
+    } else {
+      parameter = Handle<Object>(frame->GetParameter(i));
+    }
     RETURN_IF_EMPTY_HANDLE_VALUE(
         isolate,
         SetProperty(local_scope,
                     scope_info.parameter_name(i),
-                    Handle<Object>(frame->GetParameter(i), isolate),
+                    parameter,
                     NONE,
                     kNonStrictMode),
         Handle<JSObject>());
   }
 
   // Second fill all stack locals.
   for (int i = 0; i < scope_info.number_of_stack_slots(); ++i) {
+    Handle<Object> expression;
+    if (frame->is_optimized()) {
+      expression = Handle<Object>(deoptimized_frame.GetExpression(i));
+    } else {
+      expression = Handle<Object>(frame->GetExpression(i));
+    }
     RETURN_IF_EMPTY_HANDLE_VALUE(
         isolate,
         SetProperty(local_scope,
                     scope_info.stack_slot_name(i),
-                    Handle<Object>(frame->GetExpression(i), isolate),
+                    expression,
                     NONE,
                     kNonStrictMode),
         Handle<JSObject>());
   }
 
   if (scope_info.number_of_context_slots() > Context::MIN_CONTEXT_SLOTS) {
     // Third fill all context locals.
     Handle<Context> frame_context(Context::cast(frame->context()));
     Handle<Context> function_context(frame_context->declaration_context());
     if (!CopyContextLocalsToScopeObject(isolate,
@@ skipping 99 matching lines @@
 class ScopeIterator {
  public:
   enum ScopeType {
     ScopeTypeGlobal = 0,
     ScopeTypeLocal,
     ScopeTypeWith,
     ScopeTypeClosure,
     ScopeTypeCatch
   };
 
-  ScopeIterator(Isolate* isolate, JavaScriptFrame* frame)
+  ScopeIterator(Isolate* isolate,
+                JavaScriptFrame* frame,
+                int inlined_frame_index)
     : isolate_(isolate),
       frame_(frame),
+      inlined_frame_index_(inlined_frame_index),
       function_(JSFunction::cast(frame->function())),
       context_(Context::cast(frame->context())),
       local_done_(false),
       at_local_(false) {
 
     // Check whether the first scope is actually a local scope.
     if (context_->IsGlobalContext()) {
       // If there is a stack slot for .result then this local scope has been
       // created for evaluating top level code and it is not a real local scope.
       // Checking for the existence of .result seems fragile, but the scope info
@@ skipping 64 matching lines @@
     return ScopeTypeWith;
   }
 
   // Return the JavaScript object with the content of the current scope.
   Handle<JSObject> ScopeObject() {
     switch (Type()) {
       case ScopeIterator::ScopeTypeGlobal:
         return Handle<JSObject>(CurrentContext()->global());
       case ScopeIterator::ScopeTypeLocal:
         // Materialize the content of the local scope into a JSObject.
-        return MaterializeLocalScope(isolate_, frame_);
+        return MaterializeLocalScope(isolate_, frame_, inlined_frame_index_);
       case ScopeIterator::ScopeTypeWith:
         // Return the with object.
         return Handle<JSObject>(JSObject::cast(CurrentContext()->extension()));
       case ScopeIterator::ScopeTypeCatch:
         return MaterializeCatchScope(isolate_, CurrentContext());
       case ScopeIterator::ScopeTypeClosure:
         // Materialize the content of the closure scope into a JSObject.
         return MaterializeClosure(isolate_, CurrentContext());
     }
     UNREACHABLE();
@@ skipping 59 matching lines @@
       default:
         UNREACHABLE();
     }
     PrintF("\n");
   }
 #endif
 
  private:
   Isolate* isolate_;
   JavaScriptFrame* frame_;
+  int inlined_frame_index_;
   Handle<JSFunction> function_;
   Handle<Context> context_;
   bool local_done_;
   bool at_local_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(ScopeIterator);
 };
 
 
 RUNTIME_FUNCTION(MaybeObject*, Runtime_GetScopeCount) {
   HandleScope scope(isolate);
   ASSERT(args.length() == 2);
 
   // Check arguments.
   Object* check;
   { MaybeObject* maybe_check = Runtime_CheckExecutionState(
       RUNTIME_ARGUMENTS(isolate, args));
     if (!maybe_check->ToObject(&check)) return maybe_check;
   }
   CONVERT_CHECKED(Smi, wrapped_id, args[1]);
 
   // Get the frame where the debugging is performed.
   StackFrame::Id id = UnwrapFrameId(wrapped_id);
   JavaScriptFrameIterator it(isolate, id);
   JavaScriptFrame* frame = it.frame();
 
   // Count the visible scopes.
   int n = 0;
-  for (ScopeIterator it(isolate, frame); !it.Done(); it.Next()) {
+  for (ScopeIterator it(isolate, frame, 0);
+       !it.Done();
+       it.Next()) {
     n++;
   }
 
   return Smi::FromInt(n);
 }
 
 
 static const int kScopeDetailsTypeIndex = 0;
 static const int kScopeDetailsObjectIndex = 1;
 static const int kScopeDetailsSize = 2;
 
 // Return an array with scope details
 // args[0]: number: break id
 // args[1]: number: frame index
-// args[2]: number: scope index
+// args[2]: number: inlined frame index
+// args[3]: number: scope index
 //
 // The array returned contains the following information:
 // 0: Scope type
 // 1: Scope object
 RUNTIME_FUNCTION(MaybeObject*, Runtime_GetScopeDetails) {
   HandleScope scope(isolate);
-  ASSERT(args.length() == 3);
+  ASSERT(args.length() == 4);
 
   // Check arguments.
   Object* check;
   { MaybeObject* maybe_check = Runtime_CheckExecutionState(
       RUNTIME_ARGUMENTS(isolate, args));
     if (!maybe_check->ToObject(&check)) return maybe_check;
   }
   CONVERT_CHECKED(Smi, wrapped_id, args[1]);
-  CONVERT_NUMBER_CHECKED(int, index, Int32, args[2]);
+  CONVERT_NUMBER_CHECKED(int, inlined_frame_index, Int32, args[2]);
+  CONVERT_NUMBER_CHECKED(int, index, Int32, args[3]);
 
   // Get the frame where the debugging is performed.
   StackFrame::Id id = UnwrapFrameId(wrapped_id);
   JavaScriptFrameIterator frame_it(isolate, id);
   JavaScriptFrame* frame = frame_it.frame();
 
   // Find the requested scope.
   int n = 0;
-  ScopeIterator it(isolate, frame);
+  ScopeIterator it(isolate, frame, inlined_frame_index);
   for (; !it.Done() && n < index; it.Next()) {
     n++;
   }
   if (it.Done()) {
     return isolate->heap()->undefined_value();
   }
 
   // Calculate the size of the result.
   int details_size = kScopeDetailsSize;
   Handle<FixedArray> details = isolate->factory()->NewFixedArray(details_size);
 
   // Fill in scope details.
   details->set(kScopeDetailsTypeIndex, Smi::FromInt(it.Type()));
   Handle<JSObject> scope_object = it.ScopeObject();
   RETURN_IF_EMPTY_HANDLE(isolate, scope_object);
   details->set(kScopeDetailsObjectIndex, *scope_object);
 
   return *isolate->factory()->NewJSArrayWithElements(details);
 }
 
 
 RUNTIME_FUNCTION(MaybeObject*, Runtime_DebugPrintScopes) {
   HandleScope scope(isolate);
   ASSERT(args.length() == 0);
 
 #ifdef DEBUG
   // Print the scopes for the top frame.
   StackFrameLocator locator;
   JavaScriptFrame* frame = locator.FindJavaScriptFrame(0);
-  for (ScopeIterator it(isolate, frame); !it.Done(); it.Next()) {
+  for (ScopeIterator it(isolate, frame, 0);
+       !it.Done();
+       it.Next()) {
     it.DebugPrint();
   }
 #endif
   return isolate->heap()->undefined_value();
 }
 
 
 RUNTIME_FUNCTION(MaybeObject*, Runtime_GetThreadCount) {
   HandleScope scope(isolate);
   ASSERT(args.length() == 1);
@@ skipping 372 matching lines @@
         isolate->factory()->NewWithContext(function, new_previous, extension);
   }
   return scope.CloseAndEscape(new_current);
 }
 
 
 // Helper function to find or create the arguments object for
 // Runtime_DebugEvaluate.
 static Handle<Object> GetArgumentsObject(Isolate* isolate,
                                          JavaScriptFrame* frame,
+                                         int inlined_frame_index,
                                          Handle<JSFunction> function,
                                          Handle<SerializedScopeInfo> scope_info,
                                          const ScopeInfo<>* sinfo,
                                          Handle<Context> function_context) {
   // Try to find the value of 'arguments' to pass as parameter. If it is not
   // found (that is the debugged function does not reference 'arguments' and
   // does not support eval) then create an 'arguments' object.
   int index;
   if (sinfo->number_of_stack_slots() > 0) {
     index = scope_info->StackSlotIndex(isolate->heap()->arguments_symbol());
     if (index != -1) {
+      CHECK(false);
       return Handle<Object>(frame->GetExpression(index), isolate);
     }
   }
 
   if (sinfo->number_of_context_slots() > Context::MIN_CONTEXT_SLOTS) {
     index = scope_info->ContextSlotIndex(isolate->heap()->arguments_symbol(),
                                          NULL);
     if (index != -1) {
       return Handle<Object>(function_context->get(index), isolate);
     }
   }
 
-  const int length = frame->ComputeParametersCount();
+  ScopedDeoptimizedFrameInfo deoptimized_frame(
+      frame, inlined_frame_index, isolate);
+
+  int length;
+  if (frame->is_optimized()) {
+    length = deoptimized_frame.parameters_count();
+  } else {
+    length = frame->ComputeParametersCount();
+  }
   Handle<JSObject> arguments =
       isolate->factory()->NewArgumentsObject(function, length);
   Handle<FixedArray> array = isolate->factory()->NewFixedArray(length);
 
   AssertNoAllocation no_gc;
   WriteBarrierMode mode = array->GetWriteBarrierMode(no_gc);
   for (int i = 0; i < length; i++) {
-    array->set(i, frame->GetParameter(i), mode);
+    if (frame->is_optimized()) {
+      array->set(i, deoptimized_frame.GetParameter(i), mode);
+    } else {
+      array->set(i, frame->GetParameter(i), mode);
+    }
   }
   arguments->set_elements(*array);
   return arguments;
 }
 
 
 static const char kSourceStr[] =
     "(function(arguments,__source__){return eval(__source__);})";
 
 
 // Evaluate a piece of JavaScript in the context of a stack frame for
 // debugging. This is accomplished by creating a new context which in its
 // extension part has all the parameters and locals of the function on the
 // stack frame. A function which calls eval with the code to evaluate is then
 // compiled in this context and called in this context. As this context
 // replaces the context of the function on the stack frame a new (empty)
 // function is created as well to be used as the closure for the context.
 // This function and the context acts as replacements for the function on the
 // stack frame presenting the same view of the values of parameters and
 // local variables as if the piece of JavaScript was evaluated at the point
 // where the function on the stack frame is currently stopped.
 RUNTIME_FUNCTION(MaybeObject*, Runtime_DebugEvaluate) {
   HandleScope scope(isolate);
 
   // Check the execution state and decode arguments frame and source to be
   // evaluated.
-  ASSERT(args.length() == 5);
+  ASSERT(args.length() == 6);
   Object* check_result;
   { MaybeObject* maybe_check_result = Runtime_CheckExecutionState(
       RUNTIME_ARGUMENTS(isolate, args));
     if (!maybe_check_result->ToObject(&check_result)) {
       return maybe_check_result;
     }
   }
   CONVERT_CHECKED(Smi, wrapped_id, args[1]);
-  CONVERT_ARG_CHECKED(String, source, 2);
-  CONVERT_BOOLEAN_CHECKED(disable_break, args[3]);
-  Handle<Object> additional_context(args[4]);
+  CONVERT_NUMBER_CHECKED(int, inlined_frame_index, Int32, args[2]);
+  CONVERT_ARG_CHECKED(String, source, 3);
+  CONVERT_BOOLEAN_CHECKED(disable_break, args[4]);
+  Handle<Object> additional_context(args[5]);
 
   // Handle the processing of break.
   DisableBreak disable_break_save(disable_break);
 
   // Get the frame where the debugging is performed.
   StackFrame::Id id = UnwrapFrameId(wrapped_id);
   JavaScriptFrameIterator it(isolate, id);
   JavaScriptFrame* frame = it.frame();
   Handle<JSFunction> function(JSFunction::cast(frame->function()));
   Handle<SerializedScopeInfo> scope_info(function->shared()->scope_info());
@@ skipping 19 matching lines @@
       isolate->factory()->NewFunction(isolate->factory()->empty_string(),
                                       isolate->factory()->undefined_value());
   go_between->set_context(function->context());
 #ifdef DEBUG
   ScopeInfo<> go_between_sinfo(go_between->shared()->scope_info());
   ASSERT(go_between_sinfo.number_of_parameters() == 0);
   ASSERT(go_between_sinfo.number_of_context_slots() == 0);
 #endif
 
   // Materialize the content of the local scope into a JSObject.
-  Handle<JSObject> local_scope = MaterializeLocalScope(isolate, frame);
+  Handle<JSObject> local_scope = MaterializeLocalScope(
+      isolate, frame, inlined_frame_index);
   RETURN_IF_EMPTY_HANDLE(isolate, local_scope);
 
   // Allocate a new context for the debug evaluation and set the extension
   // object build.
   Handle<Context> context =
       isolate->factory()->NewFunctionContext(Context::MIN_CONTEXT_SLOTS,
                                              go_between);
   context->set_extension(*local_scope);
   // Copy any with contexts present and chain them in front of this context.
   Handle<Context> frame_context(Context::cast(frame->context()));
@@ skipping 28 matching lines @@
       isolate->factory()->NewFunctionFromSharedFunctionInfo(shared, context);
 
   // Invoke the result of the compilation to get the evaluation function.
   bool has_pending_exception;
   Handle<Object> receiver(frame->receiver(), isolate);
   Handle<Object> evaluation_function =
       Execution::Call(compiled_function, receiver, 0, NULL,
                       &has_pending_exception);
   if (has_pending_exception) return Failure::Exception();
 
-  Handle<Object> arguments = GetArgumentsObject(isolate, frame,
+  Handle<Object> arguments = GetArgumentsObject(isolate,
+                                                frame, inlined_frame_index,
                                                 function, scope_info,
                                                 &sinfo, function_context);
 
   // Invoke the evaluation function and return the result.
   const int argc = 2;
   Object** argv[argc] = { arguments.location(),
                           Handle<Object>::cast(source).location() };
   Handle<Object> result =
       Execution::Call(Handle<JSFunction>::cast(evaluation_function), receiver,
                       argc, argv, &has_pending_exception);
@@ skipping 1323 matching lines @@
   } else {
     // Handle last resort GC and make sure to allow future allocations
     // to grow the heap without causing GCs (if possible).
     isolate->counters()->gc_last_resort_from_js()->Increment();
     isolate->heap()->CollectAllGarbage(false);
   }
 }
 
 
 } }  // namespace v8::internal